Merge pull request #45 from telegram-bot-rb/update_sessions

Update sessions

README.md

@@ -199,12 +199,33 @@ end
 
 #### Session
 
-There is support for sessions using `ActiveSupport::Cache` stores.
+This API is very close to ActiveController's session API, but works different
+under the hood. Cookies can not be used to store session id or
+whole session (like CookieStore does). So it uses key-value store and `session_key`
+method to build identifier from update.
+
+Store can be one of numerous `ActiveSupport::Cache` stores.
+While `:file_store` is suitable for development and single-server deployments
+without heavy load, it doesn't scale well. Key-value databases with persistance
+like Redis are more appropriate for production use.
 
 ```ruby
-# configure store in env files:
+# In rails app store can be configured in env files:
 config.telegram_updates_controller.session_store = :redis_store, {expires_in: 1.month}
 
+# In other app it can be done for all controllers with:
+Telegram::Bot::UpdatesController.session_store = :redis_store, {expires_in: 1.month}
+# or for specific one:
+OneOfUpdatesController.session_store = :redis_store, {expires_in: 1.month}
+```
+
+Default session id is made from bot's username and `(from || chat)['id']`.
+It means that session will be the same for updates from user in every chat,
+and different for every user in the same group chat.
+To change this behavior you can override `session_key` method, or even
+define multiple sessions in single controller. For details see `Session` module.
+
+```ruby
 class Telegram::WebhookController < Telegram::Bot::UpdatesController
   include Telegram::Bot::UpdatesController::Session
   # or just shortcut:
@@ -222,12 +243,16 @@ class Telegram::WebhookController < Telegram::Bot::UpdatesController
   end
 
   private
-  # By default it uses bot's username and user's id as a session key.
-  # Chat's id is used only when `from` field is empty.
-  # Override `session_key` method to change this behavior.
+
+  # In this case session will persist for user only in specific chat.
+  # Same user in other chat will have different session.
   def session_key
-    # In this case session will persist for user only in specific chat:
-    "#{bot.username}:#{chat['id']}:#{from['id']}"
+    "#{bot.username}:#{chat['id']}:#{from['id']}" if chat && from
+  end
+
+  # This session will be the same for all updates in chat.
+  def chat_session
+    @_chat_session ||= self.class.build_session(chat && "#{bot.username}:#{chat['id']}")
   end
 end
 ```

lib/telegram/bot/railtie.rb

@@ -18,7 +18,7 @@ module Telegram
 
         ActiveSupport.on_load('telegram.bot.updates_controller') do
           self.logger = options.logger || Rails.logger
-          self.session_store = options.session_store || Rails.cache
+          self.session_store = options.session_store if options.session_store
         end
       end
 

lib/telegram/bot/updates_controller/message_context.rb

@@ -7,14 +7,11 @@ module Telegram
 
         include Session
 
-        included do
-          # As we use before_action context is cleared anyway,
-          # no matter we used it or not.
-          singleton_class.send :attr_reader, :context_handlers, :context_to_action
-          @context_handlers = {}
-        end
-
         module ClassMethods
+          def context_handlers
+            @_context_handlers ||= {}
+          end
+
           # Registers handler for context.
           #
           #     context_handler :rename do |*|
@@ -39,6 +36,8 @@ module Telegram
             context_handlers[context] = action || context
           end
 
+          attr_reader :context_to_action
+
           # Use it to use context value as action name for all contexts
           # which miss handlers.
           # For security reasons it supports only action methods and will
@@ -59,10 +58,16 @@ module Telegram
         # according to previous request.
         attr_reader :context
 
+        # Controller may have multiple sessions, let it be possible
+        # to select session for message context.
+        def message_context_session
+          session
+        end
+
         # Fetches context and finds handler for it. If message has new command,
         # it has higher priority than contextual action.
         def action_for_message
-          val = session.delete(:context)
+          val = message_context_session.delete(:context)
           @context = val && val.to_sym
           super || context && begin
             handler = handler_for_context
@@ -72,7 +77,7 @@ module Telegram
 
         # Save context for the next request.
         def save_context(context)
-          session[:context] = context
+          message_context_session[:context] = context
         end
 
         def handler_for_context

lib/telegram/bot/updates_controller/session.rb

@@ -8,19 +8,26 @@ module Telegram
       module Session
         extend ActiveSupport::Concern
 
+        module ClassMethods
+          # Builds session with given key and optional store (default to session_store).
+          # This way it's easier to define multiple custom sessions,
+          # ex. one for group chat and one for user.
+          def build_session(key, store = session_store)
+            raise 'session_store is not configured' unless store
+            key ? SessionHash.new(store, key) : NullSessionHash.new
+          end
+        end
+
         def process_action(*)
           super
         ensure
-          session.commit
+          session.commit if @_session
         end
 
         protected
 
         def session
-          @_session ||= begin
-            key = session_key
-            key ? SessionHash.new(self.class.session_store, key) : NullSessionHash.new
-          end
+          @_session ||= self.class.build_session(session_key)
         end
 
         def session_key

spec/integration/requests/default_bot_spec.rb

@@ -5,4 +5,9 @@ RSpec.describe DefaultBotController, :telegram_bot, type: :request do
     subject { -> { dispatch_command :start } }
     it { should respond_with_message 'from default' }
   end
+
+  describe '#load_session' do
+    subject { -> { dispatch_command :load_session } }
+    it { should_not raise_error }
+  end
 end

spec/integration/requests/other_bot_spec.rb

@@ -6,4 +6,9 @@ RSpec.describe OtherBotController, :telegram_bot, type: :request do
     subject { -> { dispatch_command :start } }
     it { should respond_with_message 'from other' }
   end
+
+  describe '#load_session' do
+    subject { -> { dispatch_command :load_session } }
+    it { should raise_error(/session_store is not configured/) }
+  end
 end

spec/integration_helper.rb

@@ -4,6 +4,7 @@ require 'action_dispatch'
 require 'action_dispatch/testing/integration'
 
 require 'rails'
+require 'telegram/bot/railtie'
 require 'rspec/rails/adapters'
 require 'rspec/rails/fixture_support'
 require 'rspec/rails/example/rails_example_group'
@@ -13,6 +14,7 @@ ENV['RAILS_ENV'] = 'test'
 class TestApplication < Rails::Application
   config.eager_load = false
   config.log_level = :debug
+  config.action_dispatch.show_exceptions = false
   secrets[:secret_key_base] = 'test'
   secrets[:telegram] = {
     bot: 'default_token',
@@ -34,6 +36,18 @@ Rails.application.initialize!
   Object.const_set("#{bot_name}_bot_controller".camelize, controller)
 end
 
+[DefaultBotController, OtherBotController].each do |klass|
+  klass.class_eval do
+    use_session!
+
+    define_method :load_session do |*|
+      session[:test]
+    end
+  end
+end
+
+DefaultBotController.session_store = :memory_store
+
 RSpec.configure do |config|
   config.include RSpec::Rails::RequestExampleGroup, type: :request
 

spec/telegram/bot/updates_controller/session_spec.rb

@@ -54,4 +54,45 @@ RSpec.describe Telegram::Bot::UpdatesController::Session do
       end
     end
   end
+
+  describe '.build_session' do
+    subject { controller_class.build_session(key, *args) }
+    let(:key) {}
+    let(:args) { [] }
+    it { expect { subject }.to raise_error(/session_store is not configured/) }
+
+    shared_examples 'NullSessionHash when key is not present' do |store_proc|
+      it { should be_instance_of(described_class::NullSessionHash) }
+
+      context 'and key is present' do
+        let(:key) { :test_key }
+        it 'is valid SessionHash' do
+          expect(subject).to be_instance_of(described_class::SessionHash)
+          expect(subject.id).to eq key
+          expect(subject.instance_variable_get(:@store)).to be(instance_exec(&store_proc))
+        end
+      end
+    end
+
+    context 'when store configured' do
+      before { controller_class.session_store = nil }
+      include_examples 'NullSessionHash when key is not present',
+        -> { controller_class.session_store }
+    end
+
+    context 'when store is given' do
+      let(:args) { [double(:store)] }
+      include_examples 'NullSessionHash when key is not present', -> { args[0] }
+    end
+  end
+
+  describe '.session_store=' do
+    subject { ->(val) { controller_class.session_store = val } }
+    it 'casts to AS::Cache' do
+      expect { subject[:null_store] }.to change(controller_class, :session_store).
+        to(instance_of(ActiveSupport::Cache::NullStore))
+      expect { subject[nil] }.to change(controller_class, :session_store).
+        to(instance_of(ActiveSupport::Cache::MemoryStore))
+    end
+  end
 end